Taking Whatnot to Small claims court UK

Has anyone heard of the following situation before please-

My partner has been selling on whatnot for about 9 months now. She doesn’t do live streams. Just lists items in her shop. She sells Jellycat teddys.

A lot of her sales are from a whatnot ‘influencer’ I guess who will buys bundles from my partner and sell on her stream or do give aways etc I dunno.

She is a repeat customer and her orders are typically for a £1000+

Other sales come from other people organically as expected.

Any way. My partner had about £600 in her selling account for items she had already posted and got hit with a ban.

She is unable to log in so cannot see any information.

She did receive a PDF printout with a postage label for her most recent order to be posted. This was for an order that was placed before the ban but has not been posted yet.

After a bit of back and forth from the useless support, what not are accusing her of breach of term and conditions and are withholding the balance.

She has been trying for weeks to get a better explanation but the best reply received was for something along the lines of ‘manipulating referral credits’.

For context, my partner had never referred anyone nor has received any referral credits.

I also have my own what not account and live in the same house and I have referred 1 person from my work, received a £10 credit and have used the credit.

We sent a letter last week to their UK, US and Ireland address threatening legal action.

We have not heard a response so will now be opening a claim in court.

Despite pleading for a simple explanation. All we get is “after an extensive review we stand by our decision and will not be paying out funds as per Terms and conditions”

This is absolute lunacy surely!?