dissatisfactory service from vending solutions

we purchased a refurbished vending machine through this company in August 2017. 2 months down the line we had problems and i had to continuously contact them to come and sort out the problems we were experiencing. the note reader and coin dispenser has been giving problems from the start. 20 June this year we paid 650.00 for a call out fee to have the note reader repaired. the technician advised it was just a setting that needed to be changed. the past 2 weeks we have been experiencing the exact same problem, settings are all correct and i am advised to pay the call out fee again. i am beyond angry with the service please see their response to me I’ve spoken to our M.D. – he has informed me that the Call-Out is applicable as the first 90 day of installation has now expired.

All work done carries a 15 days warranty from completion.

Kindly advise further.