not keeping to the deal

I took my bike in for repairs at hag mc.after a couple of months i started to query about my bike witch he kept telling me his waiting for parts so I phoned the mechanic that was working on the bike and he told me that he got into an accident with the.i phoned johan about the story and so we agreed that he will pay tha installment every month.things went good for a couple of months then he started paying later and later every month..now i have to remind him every month to pay and sometime he ignores the messages then he pays when he feels like it.he also promised to settle the bike witch never happened...now I'm in a constant struggle every month to get my payment..