Hitron CODA56 Activation issues and slow speed

I purchased a new CODA56 to replace my Xfinity modem. I first called Xfinity at 8 a.m. today. After 6+ hours on the phone with different reps, there is still no resolution. One rep added the wrong mac id, and the next rep added a different modem. Then, once the modem was added, they removed my internet plan entirely from my account. I had to Google the modem issue to walk a rep through getting myself a solution. One of the reps told me I needed to change the password to my Xfinity account (not my Wi-Fi) and that would fix my Wi-Fi issues... I'm at a loss for words with the experience I’ve had today dealing with Xfinity.  Currently, as of now, my modem has internet, but my speeds are still capped at 150mbs yet my plan allows for 2 gigabytes. The last rep said they were going to send "super strong signals" over the next 1-2 hours to my modem, and he was supposed to call me back 2 hours ago.... I'm not even sure what to do at this point.