Ackerman's dont want to allocate my payment

Im not happy with the service im getting from Ackermans, i paid my account using Ozow on the 06 of November. after few days checking my balance on da statement, its wasnt reflecting and i check on my bank app what ive done wrong ive found out that ive missed wit one number on my reference of which is my account number. Ive sent them proof of payment on the 10, they never responded. Went to the store yesterday da 12 they said i must send again n i jst did dat. They never responded til nw, its nt the first tym they r doin this to me. April i made a payment online cz they hv sent sms wit details of where i must pay, i did jst dat. After few days my account is in arreas when i asked they say i didnt pay ive sent them proof of payment several times the matter wasnt resolved. April i paid R190 on the 06 ive sent R400....m very angry and dissapointed