I don't understand that panic, first thing you have to learn when participating in group buys is patience. Some are finished in 1 week, some take almost a year or more (Round 5 for example). You should also check and know who you send your money, read through old threads, and make yourself an image of the person who leads the group buy. If you're not comfortable and feel scared, you can always buy at shops or 'real' group buy sites like PMK or Massdrop, or buy in the classifieds finished sets.
Using PayPal as a communication form for disputes is really not a good idea, as Ivan already mentioned. If all money is frozen because on some disputes (as it happened in the past already in other group buys), everyone has to suffer because of the fear of a few.