Taking my business elsewhere after years of service. Adding byod lines to already existing account.

I'm finally done with xfinity. I'm what they call a "gold star customer"? I've been with xfinity for about 12 years in my current home. I got rid of xfinity for a short time when I first moved in because they sold me on 1gig home internet when it first rolled out that never worked. I built up so much credit for service calls that I decided to get cellphone service and a much slower home internet service and didn't have a bill for almost 2 years because of the amounts of credits from service calls. I decided to switch my other two phones that are on the walmart family mobile over to my existing xfinity cellphone service a couple weeks ago. I have unlocked phones on a different service just in case ones service acts up I can use the other. I placed an order for the 2 byod sim kits and added the lines 2 weeks ago. Once the cards shipped I started watching the tracking daily to make sure I would ve home when they showed up. Now comes the fun part.  Today is the 19th of December.  I was supposed to have the sim kits on the 12th. Ups didn't get the sim kits to my local area until the 12th at which point they sent them over to the usps hub. Usps has no record of it ever showing up. It's been a week and it's lost in the mail somewhere. So far today I have been on the phone with 2 xfinity support calls 3 support chats and 1 visit to the local xfinity store. Every one of them treated me like I was stupid. The chats and calls only resulted in a "we are showing an expected delivery of by end of day on the tracking, here is your tracking number to track your package if you have further questions". Funny because the tracking has been saying the same thing for a week now and gets updated to the next day by end of day for a week now. Nobody seems to understand what a lost package is. Go to the local xfinity store and get told my phones won't work on the network and I need to buy two new phones. Funny because the imei check online said it would work. The online order won't even let you order the kits until you give it an imei that is compatible with the network so how could I order the kits if they where not compatible? Asked to get the sim kits in store and again I'm told no because the phones won't work on the network and no because the kits are due to be delivered. Ask them to cancel my order to which they tell me no because the sim kit order is due to be delivered today. Come home livid get ahold of chat support again go through it all one last time to be told no. Start cursing at them and they finally cancel the order. Still won't take the charges off my account so now I'm still stuck paying for 2 lines I never got for this current month and apparently the months moving forward because it still shows the two lines as being active. So I decided to call up tmobile and start service there and take my business over to them. I'll return the galaxy watches ive had for a few months now but my phones are all paid off and unlocked so those are mine. Don't go through xfinity the customer service has gone down hill in the last 10 years. They lied to me in store and the people online and on the phone where of no help at all until you finally lose your temper at them which should never be required in a customer service industry. I'm a store manager in the customer service field and I have never seen such horrible customer service and to be honest if my people ever provided such poor customer service I would walk them out the door immediately. The part that made me the most angry was the in store person had the nerve to lie to me to up sell in order to pad their pocket with their commission. I'm sorry but an unlocked sim card style s21 plus is most definitely compatible on the xfinity network because I already inserted my sim from my existing xfinity phone to verify and the online checker also verified it. I work on commissions as well and I constantly steal customers not only from my competition stores but also my own companies neighboring cities stores because I do right by the customer. I'm constantly the highest selling retail salesperson in my area beating stores that have 2-3x the monthly sales as my store. I can tell you the poor customer service and the lies to the customer has turned me off of xfinity for life this time. It's unacceptable and down right criminal. I don't think xfinity could do anything at this point to keep me as a current or future customer ever again but I would still be willing to hear them out in fairness.