Standard credit issues

I have been caught in the middle of a credit issue due to a failure at Standard bank. I had a credit card with Standardbank which I closed in 2016. With the credit card, standard bank had enrolled me with their loyalty program Ucount which had a R20 subscription. I noticed in 2017 that Standard bank continued to bill me the Ucount rewards even though the credit card was closed, therefore they could not get their subs. To that effect, I was listed in ITC as being behind in payments for a program I do not use. In 2017, I called them and they promised that all will be sorted and they will update credit bereau. Now in Oct 2018 while busy applying for a homeloan, I am told that I have outstanding payments of R200 from the same thing. How many times must I ask Standardbank to close this? Now I am about to lose a home because of Standard bank. I've exhausted all avenues to get this sorted.