Booking.com Flight Booking Change Of Dates

I purchased a round-trip Asky Airlines ticket from Yaounde to Lagos for travel between 25 March and 4 April. I am trying to change my flight dates to 28 March for departure and 6 April for return, but when I attempt to make this change, I consistently receive an error and the process does not go through. Because of this technical issue, I have been unable to modify my reservation myself. I contacted Asky customer service about the problem, but I have not received any response so far and my travel date is approaching. I kindly request that my Yaounde–Lagos round-trip ticket be changed to the new dates of 28 March to 6 April and that I be assisted in completing this change without further delays, as the current error is preventing me from managing my booking.