Is a month too long?

More than a month ago, I paid for a custom add-on from one of the better-reviewed mod sellers in this forum. When he finally installed it and I did a test-run, I discovered that using the add-on led to strange messages popping up on both the product page and the homepage. I have patiently and politely asked this developer to please fix the problem but he is now ignoring my emails! Any advice?

Patience and politeness are good things. As long as you keep asking for status updates. Make sure that the issue is well understood and ask for confirmation if this is unclear. Ask when they expect to have the issue resolved.

If the developer keeps breaking their own deadline, then ask about this and let him know that you want to have this resolved swiftly as you have been waiting.

If the developer is ignoring your emails, then make use of their ticketing system, so that you can see that its received. It could be useful to make clear that you share your experiences with this forum.

I see that some of the better reviewed addon providers seem to take on more work than they can handle. I am currently waiting for fixes from Alt-Team for 17 days now, while they stated to address the 5 issues with 4 addons within 2 business days.

That's one of the disadvantages of paying up front (assuming you did). He already has your money so why should you be a priority? Not the way to make friends and influence people though.

Thank you, P-Pharma, for your thoughtful, informative note. I will put your recommendations into practice and wait to see what happens.

Perhaps the problems could be solved with better communication from the developers and more realistic deadlines given to the customers.

I did not think to negotiate a deal whereby I pay only a percentage upfront before the work is completed and bug-free. This is how one typically pays, say, home improvement contractor, as they are known to disappear without finishing their work. It didn't occur to me that the same issue might plague the presumably small world of cs-cart mod developers.

Is this the way most of you pay for custom work? If so, I will be sure to ask for it when I have the next large mod written for me. Is there a % formula most of you use, such as 50% to start and 50% upon bug-free completion?