I think that you may have answered your own question here.
Techniclutch is a trading name for NCD (National Clutch Distributors)
Unfortunately they are known for supplying cheaper non compatible Exedy parts in Exedy boxes
Exedy UK are aware of this practice, however they appear to be reluctant to get involved.
The only way to know for sure is to compare the part numbers stamped on you old clutch kit with the one fitted as the parts look similar.
I have these numbers saved some where, and as you will have guessed by now, I have had similar issues with NCD.
Always good practice to swop the fly at the same time as the clutch, however I do not think that is your issue.