If it's been more than a year since install I doubt you'll get them to do anything. Are you sure it was from the dish? It's extremely rare that this would happen. I've been installing for 11 years and I've only seen it like twice from mounts that were installed in the 90s. I've even seen mounts with no sealant never leak. And also if your roof has been done anytime after install, the roofers actually do more harm than good putting them back on. It's more likely to leak after a roofer puts a mount on than a dish tech putting it on.