Electrical engineer

We have recently bought a core & shell premises where there is not meter installed, but the lead supply is available inside the premises. it is 3 x 100 amp lead supply and we been trying EDF to come and install the meter but they are requesting an MPAN from UK power networks. EDF is asking us do we need 3 different meters ( 100 amps x 3) or 1 meter of 300 amp. we don't know what to say. EDF also mentioned that if it is more than 100 amp they are not authorised to get the MPAN and hence we should do it ourselves. we need an engineer to come down at our premises in E14 9DS and help us sort this out. (please provide us an rough estimate). Regards