Ups Courier - Courier charges related

I open account in ups.com to send parcels in outside india.
I signed rate for the usa as around *** rs per kg. I send * parcels to isa and it delivered nicely and also i paid the invoices for that.

I send one courier to the canada. He didn't inform me that it will be charged * times higher than usa **** per kg. they made *****rs invoice for forward shipping. They pick up without giving me the rate. After that they email me that your courier cannot be delivered due to some documents related reason. And they marked it as RTO. And made another invoice of *****rs. Means **** ra per kg. Also i never get this parcel back after a year and not delivered. It's lost. I ask for the clarification for this. But they only said to pay this. I said them i will not pay until i didn't get satisfied for this * questions. One is where is my parcel. Second is why i have to pay the rate you decided without informing me. If the charges is * to * times higher than you should inform me before pick up.


Now they send me legal notice to pay this * invoices. But not resolve my * questions till now. Why should I pay. Please help me