Next generation wireless systems represent an heterogeneous environment encompassing different radio access network technologies (RATs) that differ in bandwidth, latency or cost. At the same time, mobile devices can now support multiple radio network interfaces and are therefore able to select from various available multiple heterogeneous access networks the most appropriate one in order to satisfy specific application requirements, according to the "Always Best Connected and Served" model. To support this model, the paper builds on the concept of federation agreements that allow for the collaboration of multiple service providers and exposes a series of churning scenarios in heterogeneous environments, incorporating also financial incentives for both customers and service providers. The paper formulates the relevant scenarios as non-cooperative games in order to perform admission and load control and then through simulation assesses their outcomes, to be expressed in terms of Quality of Service (QoS), income or cost.