its up 2 you if you want put them bi monthly and maybe charge extra,if you do bi monthly that is offer that option
whats there reason each time?
iv had a few say it to me but the reasons are ok like some work being done on house or getting new windows fitted that say not this time but to be honest id ask why, if its a poor excuse i would just stop doing them cant be arsed with liars,not very professional i no but cant help how i feel about it