Must the Access Provider refund any sum to the Access Seeker on any payment made in advance if the Access Agreement is terminated with SKMM approval?

Yes, subsection 5.17.9 of the MSA provides for upfront charges to be refunded on termination of an Access Agreement or access to any facilities or services provided under it, the Access Provider shall refund to the Access Seeker all amounts paid in 

advance to the extent that the amount (or part of the amount calculated on a prorata basis) relate to the period after the date of effect of such termination. 
 

This must be read together with subsection 5.7.26 of the MSA on ordering and provisioning.