What would you say was reasonable delivery time?

I sold an Item on ebay 7days ago and I emailed yesterday appologised for not getting the part in post yet and promised to post out first thing monday morning.

Is this a reasonable turn around? Basically I've been posting stuff all week and working full time I didn't get them all off straight away.

'Cos i've been getting attitude for not posting quicker! feel like refunding the paypal and telling them to fuck themselves