Please give me my paid up letter

I really do not understand how things work with Vertex. I was handed over by Finbond and even then the accounts were paid but never updated by Finbond. Vertex told me over the phone my balance is R388 and I pad that R388 few days after being told. Next thing I still get calls about non payment and I told the caller I settled the R388 and sent proof of payment. For some reason that was not updated and someone keeps sending me emails about the outsanding balance. On Tuesday I got a call from Vertex and I explained that I paid the amount I was quoted and I therefore need a paid up letter. The consultant spoke to her manager and came back and said it is fine I must send my R388 POP to queries and I will get my paid up letter. I am tired of this up and down can someone lidten to the records of my calls and give me my paid up letter because whatever balance I am told, it was added after I had paid and my payment not updated by vertex.