I’ve organised a hen do where many attended for different days/nights and, although complicated, managed to work out a fair division of the charges applied to each hen according to what they were ‘costing’ over a 3 night residential self catered weekend, with external spa visits, etc.
If you don’t get a reply from the Bride over the weekend, as others have suggested, it does seem that you’ve been eliminated from the invitation list but you are not being given the common courtesy of a simple text saying sorry, but numbers, blah blah ….. etc. She doesn’t deserve your reluctance to bow out without claiming your money back.
As you originally paid £50 as a deposit for a day and evening at a venue closer to you and this later changed requiring an overnight stay, I think you should contact the hen organiser and say you would like the money refunded.
The estimated costs are simple to work out, based on meal / drinks price, activity, etc. and you’ll then realise your £50 won’t be much compared to the individual costs for others attending for the whole lot.
You shouldn’t lose your £50 - if you feel embarrassed to ask for it back, wouldn’t you rather it go to a charity of your choice rather than to subsidise a selfish and discourteous friend who is too cowardly to contact you.
Value yourself! You’ve been excluded from the hen do group chats and are being deliberately kept in the dark. Just send your bank info. to the hen organiser and ask for £50 to be transferred back immediately with a simple explanation that you feel disconnected from the group and haven’t wanted to pressure the bride. Suggest the easiest solution for everyone concerned is to have your funds refunded immediately. Your part of the overall costs won’t have been finalised yet as final numbers for activities, meals, etc. are probably due around now.
Good luck