The big money maker for credit card companies is charging you fees. Look on your statement for monthly fees. You can and should get a rate of 1.5% or less. If your monthly fee is over 5.00, it's too much. Don't sign up with someone who calls you on the phone and wants to charge you 49.95 a month for a machine. You can buy a new or used machine outright. Don't lease it!! The money goes in the salesmans pocket. Your financing his income.
Go to your bank, tell them you have a machine, they will have you bring it in or have someone come out and program it.
If they won't do that, call someone else, like North America Bank Card. They are online. Don't have the number handy. They will reprogram your machine for 75.00 I think and take care of your transactions.