ok so MQw8QZvYYT94aKn5R8GLVKiMJrZJbF34JL is the exchange address, right?
So the real transaction in question is 800792bff2c3030057991857398eef30a2e752e12559ceb332e4a1ecd4259ae0
which the block chain shows 2 LTC came from LgQuC9H6CwY3i1pHVaa63uJaVBQtXLCcpR - which is your address verified by the screenshot where you show the inputs. The other part, 1.99 LTC came from address MU73XPDzsisy1DJRYTsxzN12vs2z5xxogM which, while not on your input screen has to be your address because it is part of transaction 800792bff2c3030057991857398eef30a2e752e12559ceb332e4a1ecd4259ae0 which was sent by you.
The reason why it may not on your list of inputs is that the address is now empty and thus no inputs.
So, yes you sent the 4.29 LTC to the exchange and they need to explain why they did not put all 4.29 LTC in your account.
You need to show them the transaction in the above screenshot where two of your addresses using a total of 6 inputs sent 4.29 LTC to MQw8QZvYYT94aKn5R8GLVKiMJrZJbF34JL with .20768479 LTC going to your change address MDUALrkDxdE2teQ7cWFcwJoTSDfp19tQCY on transaction id 800792bff2c3030057991857398eef30a2e752e12559ceb332e4a1ecd4259ae0
then MQw8QZvYYT94aKn5R8GLVKiMJrZJbF34JL split it with 2.27 LTC going to your exchange wallet MTKVhquft5dV4cKapbN9TtKFnRnrcwPotk and 2.0199834 LTC going to MFYseFNeFYVttPNoUNvupCnm7G7hZ6y8Ss
btw - the 2.0199834 LTC still sits on MFYseFNeFYVttPNoUNvupCnm7G7hZ6y8Ss