Your most important option, I think, is the ability to spread the word far and wide about this repair shop if they attempt to weasel out of their responsibility. For one thing, since you took it to them instead of doing the work yourself, you probably checked to see that they are an “authorized” repair facility for the manufacturer. The manufacturer will care greatly about who they give authorization to; if you get screwed by shoddy “authorized” repair work, then their accreditation may be revoked by the manufacturer, and there goes a lot of their business.

Be polite – of course you will be – but make them see the light, that it’s a significant bother for you to have to follow up with this repeat visit. If you had the problem yesterday you would have mentioned it to them yesterday. You’re not trying to get free work done; you’re trying to be made whole again.

If this is a small shop, find out who the owner is and speak to him/her about the issue. The owner has a heavy stake in the result; the average careless or indifferent technician, not so much.

Thanks you two. I brought it back today and they’re working on it free of charge, the most I had to do was ask “will I be charged for that?” which pleased non-confrontational me.