A very poor and inconvenient service provider

I recently joined Telkom with the hope of enjoying its services but it is going to a different direction, one of their service advisors called after i had made a request on a deal i saw online and assisted me in signing up for that deal, we then proceeded to the billing information to which the advisor asked me of a date i would like to be debited and i committed for the 26th of every month, a debi check was then sent to my banking app for approval, i then approved after seeing the noted date as the one i had agreed to during my telephone conversation with the advisor, The 26th went past and i started to receive SMSs that I've missed a payment to my surprise the debit order didn't go through on the agreed date, for what reason I'm sure i wouldn't know, This is an inconvenience to my financial plans and commitments, now my bill has sky rocketed to a figure i am sure i will not settle because i don't think that is fair for Telkom to just take such incorrect actions without reviewing my agreement document, now they are busy hitting me with charges of late payment. worst part for you to call them you need to be their client, they are unreachable, i have no other way but to reach them with legal action, i keep asking to speak with any supervisor but they refuse, i will have to fish them out myself