I too had a hard time when mum got in a muddle with her, fortunately non-critical, medication. We tried a dossette box, but mum found it hard to cope with partly due to dementia and partly due to poor eyesight. She also didn't think she was having problems and found the whole thing patronising. Mum wouldn't accept carers either, but I think that if you can persuade your aunt to accept someone coming in to help her take them that will be probably be the best solution at the moment.
The pill problem was one of the red flags that made me realise a care home was the best option, and when mum moved to one, she too the medication without problem.