Where to best buy mosquito zapper rackets and nets

Hello - New in Chiang Mai and bought some rackets and a net because my airbnb is not quite as described. None of the rackets work - and very expensive - and the net doesn't fit the bed. In Vietnam, the best place to buy mosquito rackets was the local markets. The expensive ones in the Western supermarkets never worked at all. Any suggestions please as to where I should go in Chaing Mai today? Thanks!

Are those rackets really practical? It's a bug-zapper thing, right? You have to chase down individual skeeters and swing the thing through them. I guess they are fairly cheap.

Probably your best bet is using lots of DEET and getting a bigger net.