IMO, at present there's no evidence of a statutory defence for you.
The list in an earlier post is purely speculative or prospective and doesn't bear upon the facts as known i.e. you parked in a clearly and properly (as in adequately) marked bay.
1) PCSO uniform not compliant, - speculative as you weren't there and didn't see them;
2) The copy of the PCN that they produce at the tribunal is not a true copy of the original, as per Vanessa Price v Nottingham City Council (NG00044-2201, 7 March 2022) and Tahir Hamid v London Borough of Waltham Forest (2220519865, 9 August 2022)- speculative, it hasn't happened yet;
3) The notice of rejection is ambiguous - similarly speculative.*
TfL often re-offer a discounted sum but whether this is contingent upon the reps being submitted no later than day 14 I'm not sure. If it is then submit reps to arrive no later than Mon. 15th(day 14), which means post first class no later than 11th and get proof of posting.
*- while the speculation might be based on recorded deficiencies in other cases, you should be aware that the same may not apply in your case. Items 2 and 3 would become evident on receipt of a rejection hence why attempting to maintain the discounted level of penalty is important.
