Very BAD service!!

They developed an MT4 indicator for me, but there is a problem with the results of one of the routines they have programmed. After at least 5 requests to them to have a look at this and fix the problem they just totally ignore me. Not even acknowledging my e-mails or saying they are not prepared to do it. I offered to pay for the fix (which should actually be free because they created the error) but they just ignore all attempts to communicate with them.