Overcharges by nearly quadruple my normal billing support says they fix it but marked after month I have to address

I've been overcharged and the contended to repeat the behavior every month every month I call and fix it and they say I won't have to deal with it next month I receive a $30 ACP discount at a $10 auto pay discount my normal bill is 70 a month so my toilet should be over 30 a month and from May until December of 2023 on a 2-year contract with a guaranteed locked in rate My bill is always been 30 a month but for January and February of this month the total has been 40 with discounts as of recently they say one of my recent payments despite using the same payment method was refused by my bank My bank says they did not refuse a payment of that Xfinity is at fault and they must have a processing error upon reporting this they said they would give me $70 credit issued a January I let my bill would be less than the $30 that I normally pay however in February on my February 5th billing it was over $100 I paid that balance even though it was unfair and told them that future amounts only be $30 a month according to the times of the two-year contract Now they're talking about increasing the price even though I'm on a two-year contract locked in to not increase they're going to increase it by $3 and on top of that the $70 credits must not have applied because they're overcharging me $70 due in March plus the $30 normal bill stating that I have a one-time charge of $30 at a forwarded charge $40 for a total of $70 charges that credits were supposed to take care of plus my normal $30 internet bill is $100 I am on a SSI check raising a family on one single limited budget this issue is supposed to be resolved month after month it is not I want consistent billing I want the agreement that was made and did not want to be charged for a returned check fee due to their processing error and I was promised $70 in credits and I see that they were applied the previous month but then the carrying over the charge to charge me for the $70 again after credits were supposed to take care of it they'll recharging the $70 to me again this month along with the 30 $100 bill that is supposed to be only $30 this is nearly four times overcharge such a gross overcharge demands that I report this one to the FCC the federal trades commission and file a complaint with the better Business Bureau along with the BCA Reach me how to support they only say Yes we see you're always supposed to get $30 a month charge but we've been charging you 40 your bill is accurate If I complain to a supervisor I get the credits and a resolution but the issue comes up again on the following month that has been doing that for 3 months I feel I have no choice but to file a formal complaint this is step one of that documented complaint that I fully intend to file after the weekend holiday I will tolerate no more unauthorized charges