Blackberry curve 8900 like new +

Selling a blackberry 8900 bought it a few weeks ago needing a battery I have just replaced the full housing and covers so looks like brand new, screen is scratch free costing (£45) Replaced the battery with a brand new one (£6) unlocked to all networks (£10) work with vodaphone/orange/t mobile/o2 etc looks like a new phone can show it working now after all the money spent on it when i make a call it says call failed. was working before. may swap another phone