Poor service even after settling accounts they handling

I was called and told that I have 2 accounts handed over showing on their side, I paid both the accounts in one payment, I sent them an email with the proof of payment and stating that the payment must be allocated to Mpowa Finance and Fasta account yet they ddnt even respond to my emails that I always have to call them to remind them that they must allocate the payments….they told me to wait for 7 days which has passed already and to this day I am the one who is calling them and sending emails but no one is providing fees back….their service is poor