Firstly,I wouldn't worry too much about late payments.We were 6 mths overdue with ours and got taken to the cleaners for a massive 4 euro fine,how these people sleep at night is a mystery....
As for dealings and payments from the UK I can't help,there must be something that could be set up.There are a couple of people at BASE who speak limited Spanglish and it's no big deal if you are prepared to wander from BASE to bank and back again,several times.Make sure you have ALL your paperwork.