My LTCs not appear in balance nor sent after 7 days , please help!

Website wallet i sent before seven days 11.43 ltcs from my bitcoin wallet through Changelly site to them, and the transaction went smoothly without any problem in less than 5 minutes,but when I sent them back to Changelly ltc address, on the site they said that the transaction was processed, and Changelly said they did not receive any coins, I looked for this transaction with my wallet address via blockcypher,they said that my wallet balance is still as it is, and Changelly ltcs address didn’t receive any litecoins yet, I sent them mails through their site and no response at all, is there any method that enable me to restor my coins and my wallet balance, I am ready to give litecoin prize for that , your help is greatly appreciated, thank you