Raised beds

Depends what was in the garden centre compost. Bagged compost usually only has enough nutrients for a limited growing time. Pure (i.e. green waste or home made) compost has more nutrients but isn't a good growing medium for an extended period of time since it's always breaking down. Peat is low in nutrients but is naturally more resistant to degradation. The compost has likely lost most of its nutrients and compaction may have reduced its water and air holding capacity.

Soils typically only contain 5-10% organic matter, so for filling raised beds a loamy topsoil mixed with some compost is better. If the garden centre compost was mostly peat I would dig in lots of topsoil and some real compost.