cockroaches

If it's one or two you can get a spray in most supermarkets that will kill them, then spray around doors and windows. If it's lots of them then there are companies like pestsrus.es that will advise on getting rid of them if it's an infestation but it might be expensive.

Get the black tin from mercadona (not sure of name) it says 3 months on tin and it does last this long but make sure no one in room when spraying and you cover your mouth and nose -fumes are toxic!

Carrefour sell a can called 'ZUM'. It's a red can and quickly got rid of a few that we had. I still spray every other week though to be on the safe side. Like the one that deirdre42c recommends, this one also stinks. Smells like really strong wd-40. Best to spray and go out for the day. 

Go to the local ferreteria and buy some plug in repellants. Cost 8 - 10€ and are V good. Plug them in and leave them so all summer long. The cockroaches MAY still appear, but they are stunned and on their backs, one simply has to then spray the3m, wait a couple of mins and sweep them up. We have used them ourselves in Blue hills (just up the road from you) and have a friend in Blue Lagoon who is terrified of them but who can quite happily cope with them since these were installed.They simply plug in.

Normal part of life on the C Blanca at this time of year i 'm afraid!!

I've used a local company that we've used called Control Natural de Plagas, they are very professional, speak English and they guarantee their service for 6 months.  I believe that they are located in San Javier.  The number I have for them is 692863608.