Won't let me cancel in peace

Someone plz assist, January 4 I requested to cancel my contract(not easy) end of January my account was debited for R599, then Feb 1 debited for R50(dont what for).End of February was expecting debit for R599 for the last time for that 1 month notice, however they attepmted to debit R1298 fortunately I did not have this money. Now they keep trying to debit this R1298. I'e spoken to countless agents(via whassup) to no avail.