Based in the provided information, the stage according to Erikson's psychosocial development that was not successfully completed is Trust vs. Mistrust.
Erikson's psychosocial development can be expressed as the theory that stressed that personality develops in a predetermined order, and this been done in eight stages of psychosocial development.
Therefore, in the case above fall into one of this eight stages which is Trust vs. Mistrust, and this this stage is very crucial in gaining the loyalty of client and lasting relationship.
Learn more about Erikson's psychosocial development theory at:
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