Letter 2 reverse funds

Exact is a pure ****! I laybuyed clothes for my kids and paid R200. The remaining balance was around R1600,then on da 30th of June I swapped R400 at da store then on da 7th of July I went back 2 pay da remaining balance which was supposed 2 b R1200 bt when I got there they told me dat da R400 I paid on da 7th wasn't processed by capitec nonetheless I paid da amount nd got da clothes. They promised 2 revise the R400 back 2 my account bt they ddnt, then after 3days I called 2 ask abt my money they said I should claim it at capitec, I went 2 capitec they said they want a letter 4rm da store I called da store 2 ask 4 a letter even 2day I still dnt have da letter its been 3 weeks now. **** shame