Ask an Property Solicitor. Get an Answer ASAP.
Sorry to hear about the difficulties you are facing.
When you bought the property your solicitor at the time should have made you aware that this is the situation with the parking and there will be no guarantee that it can or will be changed regardless of what they said. Any negotiations should have been done before purchasing. I appreciate you were going through a lot but under the circumstances unfortunately legally you have no right for the parking to be changed. You can of course ask them and keep requesting this but there is no guarantee this will be agreed.
Hope this helps.
All the best