Greyhound Bus Line Telephone Service Fees Internet, Internet

I booked a trip to New York City last night, and was told that the total fee would be $37.00.  After checking my card I could see that I had been charged $47.00.  I called back and was told that the extra $10 was a 'service fee' for booking over the phone.  This was NEVER revealed by the booking agent, and thus seems like a scam to me.  I checked the web site --(Buy tickets over the phone. U.S. customers who call our toll-free number 1-800-231-2222 may purchase tickets using a credit card.) ---and there is nothing about paying a fee for telephone purchases.  Beware .... a scam.