Magnetic properties of polycrystalline ${\mathrm{Sm}}_{0.1}{\mathrm{Ca}}_{0.84}{\mathrm{Sr}}_{0.06}{\mathrm{MnO}}_{3}$ in pristine and metastable states have been investigated in wide range of temperatures and magnetic fields. It was found that below Curie temperature ${T}_{\mathrm{C}}\ensuremath{\approx}105\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ the pristine state exhibits phase separation comprising ferromagnetic and antiferromagnetic phases. The metastable states with reduced magnetization were obtained by a successive number of quick coolings of the sample placed in a container with a kerosene-oil mixture. By an increasing number of quick coolings $(g6)$ the long time relaxation appeared at $10\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and the magnetization reversed its sign and became strongly negative in a wide temperature range, even under an applied magnetic field of $15\phantom{\rule{0.3em}{0ex}}\mathrm{kOe}$. The observed field and temperature dependences of the magnetization in this state are reversed in comparison with the ordinary ferromagnetic ones. Above ${T}_{\mathrm{C}}$, the observed diamagnetic susceptibility of the reversed magnetization state at $T=120\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ is ${\ensuremath{\chi}}_{\mathrm{dia}}\ensuremath{\approx}\ensuremath{-}0.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}\phantom{\rule{0.3em}{0ex}}\mathrm{emu}\phantom{\rule{0.3em}{0ex}}{\mathrm{g}}^{\ensuremath{-}1}\phantom{\rule{0.2em}{0ex}}{\mathrm{Oe}}^{\ensuremath{-}1}$. Only after some storage time at room temperature, the abnormal magnetic state is erasable. It is suggested that the negative magnetization observed results from a specific coupling of the nano/microsize ferromagnetic regions with a surrounding diamagnetic matrix formed, in a puzzled way, by the repeating training (quick cooling) cycles.