At my wits end...

Hi, just joined cos I’m at my wits end with an ongoing issue.

Fitted some maxpeeding (i know, first time buyer, pretty much regret not spending a little extra) coilovers about a month ago at a garage. 
was advised at the time the drop link was on its way and possibly cos it’s new suspension new top mounts. A month later (yesterday) that’s what it was sent in for due to excessive clonking from the passenger side front. 
it came out the garage with a refund on the top mounts, new drop links fitted, a hefty bill and the knocking supposedly gone. Nonsense. 
Iv spent today checking the centre top mount bolt and still the knocking persists. in March I replaced lower arms. 
 

im now thinking it could be a driveshaft? How do I check for a bad one? If not what else could it be! I’m not willing to pay another mechanical bill for the problem to still be apparent. 
 

any help massively appreciated, I can’t upload the photos I think relevant as bigger then required apparently, all except this one of my top mount after I unbolted it.