I had an interesting experience with Renogy, which was successfully resolved. I ordered a Midnight Solar MNPC6 combiner box and breakers rated for my application only to find out they would not fit this box (at least not without using the fuse holder set up, which would then limit it to 4 breakers instead of 6. I had a note in the order instructions indicating my concern about that possibility, which was apparently overlooked.
In addition to the rather discouraging revelation that the MNPC6 would not work for my application, another big surprise occurred when I opened the boxes from Renogy. Instead of the 5 breakers I ordered, I received 5 CASES (12 breakers in each case for a total of 60)!!! Some poor soul in shipping was likely admonished if not canned for that after I brought it to their attention.
It's sad to be honest some days... Instead of listing all these breakers on eBay I initiated RMAs for the entire mess.... Tech support did thank me for letting them know
The RMA shipping label I received was for one box, instead of the two the stuff came in. I taped the two boxes together with the one label taped to the top one. Thankfully they made it back to Renogy. 2 weeks later I had yet to receive the refund, so I called. Long time on hold, but I eventually got through and they initiated the refund, which hit my card a couple of days later.
So, it all worked out fine, but it did take time. I could have made out like a bandit listing all the free breakers on eBay, but I'd have problems living with my self had I gone that route
Renogy does seem to be trying their best, as evidenced in this thread. And they do have good products for the price point. If you need a lot of hand holding, you may be better served paying more and using a company that invests more in tech support and customer service. If you're like most DIYers and looking for the best price, you really should expect to have some issues to resolve.