I would start off my acknowledging what a great client they are and how much you enjoy doing Business with them. Tell them that a few months ago you extended a discount in good faith to them and that you see that they have been able to turn Business around (as you knew they would). Then state that with the economic conditions and rising costs of doing Business you need to come to an agreement as to what the new rate should be. Ask for a phone call to determine and discuss the new rate
you accomodated them by accepting less for a temporary period of time and you should inform them that that accomodation has outrun itself, that you cannot continue to perform at the lower ratedon t be surprised tho if he terminates your servicesI had a client who rented a business space for over 30 yrs and asked the landlord for some relief when times were badthe landlord did for a short period and when he raised the rent back to the original rate, he also did not renew the lease!