Telesales / telemarketing

My gym is on a membership drive and I need someone, ideally with telesales experience, who is happy to contact leads, describe the benefits my company has and then get the clients to sign up. The leads will generally be hot (they will have met my ground staff either earlier that day, or week) and won't be surprised at the call. What I do need is someone who can close the call - we are a new gym, have a competitive price, have USPs but my ground staff aren't natural sellers so the conversion rates are low.