Your items (radiator, intercooler & fan) were ordered on 1st March (you were quoted within 3 mins of submitting your enquiry, and placed your order less than 30 mins after that). We note that you sent RB Ltd an online msg on 9th March stating "wrong parts", and also that you'd sourced alternative parts from a non-PG supplier in Preston, (without giving RB the opportunity to replace, and juxtaposed to their clearly displayed T&C's).
Previous to this, you submitted a formal PG dispute against this same supplier on 5th March at 11:46am. This was responded to by RB Ltd at 13:18, and forwarded onto you by ourselves at 13:18 the same day. There has been no other communication from you to us via our Support system etc in the 17 days since you bought these items, so we are dumbfounded as to how you can say "Parts Gateway did nothing for you"?
FYI, RB Ltd responded to your dispute by informing you that "Parts were supplied as requested, please send parts back (if not required) and we will refund minus handling charge" (as per their T&C's relating to "goods correctly supplied but no longer needed").
Note that any confusion over your order initially will have been down to you squeezing 3 parts into just one part name field instead of using the "Add Parts" link underneath (which would've allowed you to be quoted by all relevant suppliers separately (and more accurately) for each individual part.
If you are still "trying to get your money back", this is most likely due to you not yet having returned their parts as requested!